U.S. patent number 8,399,112 [Application Number 13/127,897] was granted by the patent office on 2013-03-19 for battery module and battery pack using the same.
This patent grant is currently assigned to Panasonic Corporation. The grantee listed for this patent is Shinya Geshi, Toshiki Itoi, Daisuke Kishii, Hiroshi Takasaki, Shunsuke Yasui. Invention is credited to Shinya Geshi, Toshiki Itoi, Daisuke Kishii, Hiroshi Takasaki, Shunsuke Yasui.
United States Patent |
8,399,112 |
Yasui , et al. |
March 19, 2013 |
Battery module and battery pack using the same
Abstract
A battery module 100 includes a plurality of batteries aligned
and accommodated in a housing 20, wherein each batteries has an
opening portion 17 at an electrode portion 16 of the battery to
release gas generated in the battery outside the battery, the
housing 20 is partitioned by a circuit board 30 disposed in contact
with battery cases 5 around the electrode portions 16 of the
batteries into a storage portion 54 in which the batteries are
stored, and an exhaust chamber 24 via which the gas released from
the opening portion 17 of the electrode portion 16 is exhausted
outside the housing 20, the electrode portions 16 of the batteries
are connected to a connector 32 on the circuit board 30, and the
opening portions 17 of the electrode portions 16 are in
communication with the exhaust chamber 24 via through holes 36 in
the circuit board 30.
Inventors: |
Yasui; Shunsuke (Osaka,
JP), Takasaki; Hiroshi (Osaka, JP), Itoi;
Toshiki (Nara, JP), Geshi; Shinya (Osaka,
JP), Kishii; Daisuke (Osaka, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Yasui; Shunsuke
Takasaki; Hiroshi
Itoi; Toshiki
Geshi; Shinya
Kishii; Daisuke |
Osaka
Osaka
Nara
Osaka
Osaka |
N/A
N/A
N/A
N/A
N/A |
JP
JP
JP
JP
JP |
|
|
Assignee: |
Panasonic Corporation (Osaka,
JP)
|
Family
ID: |
43449144 |
Appl.
No.: |
13/127,897 |
Filed: |
July 9, 2010 |
PCT
Filed: |
July 09, 2010 |
PCT No.: |
PCT/JP2010/004485 |
371(c)(1),(2),(4) Date: |
May 05, 2011 |
PCT
Pub. No.: |
WO2011/007533 |
PCT
Pub. Date: |
January 20, 2011 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20110212348 A1 |
Sep 1, 2011 |
|
Foreign Application Priority Data
|
|
|
|
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Jul 17, 2009 [JP] |
|
|
2009-168516 |
|
Current U.S.
Class: |
429/7;
429/82 |
Current CPC
Class: |
H01M
50/20 (20210101); H01M 50/502 (20210101); H01M
50/30 (20210101); H01M 10/425 (20130101); Y02E
60/10 (20130101) |
Current International
Class: |
H01M
10/42 (20060101) |
Field of
Search: |
;429/7,82,83 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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198 10 746 |
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Sep 1999 |
|
DE |
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2 339 672 |
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Jun 2011 |
|
EP |
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2 426 775 |
|
Mar 2012 |
|
EP |
|
2000-208118 |
|
Jul 2000 |
|
JP |
|
2000-223166 |
|
Aug 2000 |
|
JP |
|
2001-256949 |
|
Sep 2001 |
|
JP |
|
2002-134078 |
|
May 2002 |
|
JP |
|
2003-162993 |
|
Jun 2003 |
|
JP |
|
2007-027011 |
|
Feb 2007 |
|
JP |
|
2008-117756 |
|
May 2008 |
|
JP |
|
Other References
Extended European Search Report issued in European Application No.
10799597.9 issued on Jun. 22, 2012. cited by applicant.
|
Primary Examiner: Huff; Mark F
Assistant Examiner: Wills; Monique
Attorney, Agent or Firm: McDermott Will & Emery LLP
Claims
The invention claimed is:
1. A battery module comprising: a housing; a plurality of batteries
aligned and accommodated in the housing; and a circuit board
including through holes, wherein: each of the batteries has an
opening portion disposed at an electrode portion of the battery to
release gas generated in the battery outside the battery, the
circuit board is disposed in contact with battery cases around the
electrode portions of the batteries, the housing is partitioned by
the circuit board into a storage portion and an exhaust chamber so
that the plurality of batteries are stored in the storage portion
and the gas released from the opening portion is exhausted outside
the housing via the exhaust chamber, the electrode portions of the
batteries are connected to a connector formed on the circuit board,
and the electrode portions of the batteries are inserted in the
through holes such that the opening portions are in communication
with the exhaust chamber via the through holes.
2. The battery module of claim 1, wherein: the circuit board has a
layered structure including a heat-resistant member and an elastic
member, and a lower surface of the elastic member is in contact
with the battery cases.
3. The battery module of claim 1, wherein: the connector is formed
on an upper surface of the circuit board, and a lower surface of
the circuit board is in contact with the battery cases.
4. The battery module of claim 3, wherein a height of each
electrode portion is substantially the same as a thickness of the
circuit board.
5. The battery module of claim 3, wherein a size of each through
hole formed in the circuit board is smaller on a side on which the
circuit board is in contact with the battery case than on a side on
which the circuit board is provided with the connector.
6. The battery module of claim 1, wherein: the opening portion is
provided at an upper surface of the electrode portion, and the
connector connected to the electrode portions has through holes
formed at least in positions of the connector corresponding to the
opening portions.
7. The battery module of claim 6, wherein the gas released from the
opening portion is released into the exhaust chamber via the
through hole.
8. The battery module of claim 1, wherein the connector connected
to the electrode portions is formed to straddle the plurality of
through holes formed in the circuit board.
9. The battery module of claim 1, wherein: the opening portion
disposed at each electrode portion is provided at a side surface of
the electrode portion, and a gap is provided between the circuit
board and the electrode portion in each through hole formed in the
circuit board.
10. The battery module of claim 9, wherein the gas released from
the opening portion is released into the exhaust chamber through
the gap.
11. The battery module of claim 1, wherein the plurality of
batteries are connected in parallel by the connector connected to
the electrode portions of the batteries.
12. The battery module of claim 1, wherein the storage portion is
sealed by the circuit board.
13. The battery module of claim 1, wherein the housing is made of a
metal material having an insulated surface.
14. The battery module of claim 1, wherein: the housing includes a
lid body, partition portions are provided in the storage portion in
such a manner that the batteries are individually stored, and the
lid body includes rib portions at positions facing the partition
portions in the housing.
15. The battery module of claim 1, wherein: the housing includes a
lid body, and a supporting member for holding the circuit board is
further provided between the lid body and the circuit board.
16. A battery pack comprising: multiple ones of the battery module
of any one of claim 1, wherein the battery modules are aligned and
connected in series and/or parallel.
17. The battery module of claim 1, wherein the circuit board is
disposed inside the housing and a part of the circuit board extends
from the housing to outside the housing.
Description
RELATED APPLICATIONS
This application is the U.S. National Phase under 35 U.S.C.
.sctn.371 of International Application No. PCT/JP2010/004485, filed
on Jul. 9, 2010, which in turn claims the benefit of Japanese
Application No. 2009-168516, filed on Jul. 17, 2009, the
disclosures of which Applications are incorporated by reference
herein.
TECHNICAL FIELD
The present invention relates to battery modules including, in
particular, a plurality of batteries, wherein even when a problem
such as generation of heat occurs in a battery, the problem does
not influence the other batteries, and to battery packs using the
same.
BACKGROUND ART
In recent years, in view of savings in resources and conservation
of energy, there have been increasing demands for nickel-hydrogen
secondary batteries, nickel-cadmium secondary batteries, lithium
ion secondary batteries, etc. which can be used repeatedly. Among
them, lithium ion secondary batteries are characterized by
lightness in weight, high electromotive force, and high energy
density. Thus, there are growing demands for the lithium ion
secondary batteries as power sources for driving various kinds of
mobile electronic devices and portable communication devices such
as mobile phones, digital cameras, video cameras, and laptop
personal computers.
On the other hand, to reduce used amount of fossil fuel, and to
reduce the amount of emission of CO.sub.2, expectations for battery
packs are growing to serve as power sources for driving motors such
as vehicles. Such a battery pack includes a plurality of battery
modules each including one or more batteries in order to obtain a
preferable voltage and capacity.
In the development of the above battery modules, downsizing the
battery modules is a major challenge because the battery modules
for storing predetermined electric power are accommodated in
limited space, for example, in a vehicle.
For this purpose, a configuration is disclosed in which a battery
assembly (a battery module) includes a plurality of batteries, and
the connection between the batteries and an interconnect for
detecting a voltage, temperature, or the like are implemented by
patterned interconnects formed on a printed circuit board (for
example, see Patent Document 1). Likewise, a power supply device (a
battery pack) is disclosed in which a plurality of power modules
are accommodated in a holder case, and is connected to each other
by an end plate (for example, see Patent Document 2). The end plate
is provided with a sensor lead and a power-supply lead for
connecting the battery modules to each other, so that it is
possible to reduce poor connection, and downsizing can be
possible.
Moreover, as the capacity of a battery to be accommodated in a
battery module increases, heat may be generated in the battery
itself, and the battery may have a high temperature depending on
how it is utilized. Thus, in addition to the safety of the battery
itself, the safety of the battery module, which is a collection of
batteries, becomes more important. That is, the internal pressure
of the battery may be increased by gas generated due to overcharge,
overdischarge, or an internal or external short-circuit, and thus
the outer case of the battery may rupture. For this reason,
generally, a battery is provided with a vent mechanism or a safety
valve to release gas so that the gas in the battery is released.
Here, when the released gas is, for example, ignited, smoking may
occur, or in rare cases, combustion may occur, which poses a
problem with reliability and safety.
For this reason, a power supply device (battery module) is
disclosed in which a plurality of batteries are accommodated in a
battery chamber within a case, and a partitioning wall has openings
facing safety valves of the batteries, so that gas emitted from a
battery in a fault state is released from an outlet via an exhaust
chamber (for example, see Patent Document 3).
CITATION LIST
Patent Document
Patent Document 1: Japanese Patent Publication No. 2000-208118
Patent Document 2: Japanese Patent Publication No. 2000-223166
Patent Document 3: Japanese Patent Publication No. 2007-27011
SUMMARY OF THE INVENTION
Technical Problem
However, in the battery modules described in Patent Document 1 and
Patent Document 2, when excessive heat is generated in one battery
to allow the operation of the safety valve, it is not possible to
control the quantity of the heat generated in the battery, or the
influence of ignition of emitted gas over neighboring batteries,
which causes the problem of consecutively deteriorating the
batteries. That is, in a battery module including a plurality of
batteries, how expansion of the influence of a battery having a
problem over neighboring batteries is controlled to a minimum is a
problem to be solved.
Moreover, in the battery module described in Patent Document 3, the
partitioning wall of the case has the openings facing the safety
valves of the batteries so that the emitted gas does not fill the
battery chamber, but is released to the outside. However, Patent
Document 3 discloses a circuit board built in a resin, but fails to
teach or suggest, for example, a method for connecting the circuit
board to the batteries. Therefore, when a surface on a safety valve
side of each battery is connected to a connection terminal, it is
not clear how air-tightness with respect to the partitioning wall
is maintained. Moreover, it is difficult to position the safety
valve of each battery to the opening portion of the partitioning
wall, and thus positioning using recessed portions leaves space
between the batteries, so that downsizing is not possible.
Furthermore, the batteries and the circuit board are fixed and
built in a resin, which poses a problem with downsizing the battery
module.
The present invention was devised to solve the above problems. It
is an object of the present invention to provide a battery module
whose size and thickness can be reduced, and in which the influence
of excessive heat generation in a battery having a problem over
neighboring batteries can be controlled to a minimum, and a battery
pack using the same.
Solution to the Problem
To solve the above problems, a battery module of the present
invention is a battery module including a plurality of batteries
aligned and accommodated in a housing, wherein each of the
batteries has an opening portion at an electrode portion of the
battery to release gas generated in the battery outside the
battery, the housing is partitioned by a circuit board disposed in
contact with battery cases around the electrode portions of the
batteries into a storage portion in which the plurality of
batteries are stored, and an exhaust chamber via which the gas
released from the opening portion of the electrode portion is
exhausted outside the housing, the electrode portions of the
batteries are connected to a connector formed on the circuit board,
and the opening portions of the electrode portions are in
communication with the exhaust chamber via through holes formed in
the circuit board.
With this configuration, the circuit board is in contact with the
battery cases around the electrode portions of the batteries, and
the opening portions of the electrode portions are in communication
with the exhaust chamber via the through holes formed in the
circuit board. Therefore, space into which gas emitted as a result
of opening a vent mechanism of the battery is released can be
limited to be within the through hole. Thus, the gas released from
the opening portion of the electrode portion is released into the
exhaust chamber via the through hole, and is further released
outside the housing. Therefore, the gas can be prevented from
entering neighboring batteries. Moreover, space required for
routing power supply interconnects, control interconnects, etc. can
significantly be reduced by the circuit board. As a result, it is
possible to obtain a thin and small battery module which has
substantially the same height as that of the batteries, and which
is highly safe and has high reliability.
Moreover, a battery pack of the present invention includes multiple
ones of the above battery module which are connected in series
and/or parallel. With this configuration, a battery pack having a
given voltage and capacity can be obtained according to the
application.
Advantages of the Invention
According to the present invention, it is possible to obtain a
battery module and a battery pack, wherein the size and the
thickness of the battery module are reduced, and the influence of
excessive heat generation in a battery having a problem over
neighboring batteries can be controlled to a minimum.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a battery included in a battery
module of a first embodiment of the present invention.
FIG. 2A is a perspective view of the battery module of the first
embodiment of the present invention. FIG. 2B is a cross-sectional
view along the line 2B-2B of FIG. 2A. FIG. 2C is an enlarged
cross-sectional view of the part 2C of FIG. 2B.
FIG. 3 is an exploded perspective view illustrating the battery
module of the first embodiment of the present invention.
FIG. 4A is a cross-sectional view illustrating exhaustion of gas
emitted in case of, for example, excessive heat generation in one
of the batteries of the battery module of the first embodiment of
the present invention. FIG. 4B is an enlarged cross-sectional view
of the part 4B of FIG. 4A.
FIG. 5 is an exploded perspective view illustrating another example
of the battery module of the first embodiment of the present
invention.
FIG. 6 is a perspective view illustrating another example of the
lid body of the first embodiment of the present invention.
FIG. 7 is an exploded perspective view illustrating another example
of the housing of the first embodiment of the present
invention.
FIG. 8 is an exploded perspective view illustrating yet another
example of the housing of the first embodiment of the present
invention.
FIG. 9 is an enlarged cross-sectional view illustrating a part of
another example of the circuit board of the first embodiment of the
present invention.
FIG. 10 is a cross-sectional view illustrating a battery included
in a battery module of a second embodiment of the present
invention.
FIG. 11A is a perspective view of the battery module of the second
embodiment of the present invention. FIG. 11B is a cross-sectional
view along the line 11B-11B of FIG. 11A. FIG. 11C is an enlarged
cross-sectional view of the part 11C of FIG. 11B.
FIG. 12 is an exploded perspective view of the battery module of
the second embodiment of the present invention.
FIG. 13A is a cross-sectional view illustrating exhaustion of gas
emitted in case of, for example, excessive heat generation in one
of the batteries of the battery module of the second embodiment of
the present invention. FIG. 13B is an enlarged cross-sectional view
of the part 13B of FIG. 13A.
FIG. 14A is a perspective view of another example of the battery
module of the second embodiment of the present invention. FIG. 14B
is a cross-sectional view along the line 14B-14B of FIG. 14A. FIG.
14C is an enlarged cross-sectional view of the part 14C of FIG.
14B.
FIG. 15A is an assembled perspective view illustrating a battery
pack of a third embodiment of the present invention. FIG. 15B is an
assembled perspective view illustrating another example of the
battery pack of the third embodiment of the present invention.
FIG. 16 is an exploded perspective view illustrating a battery
module in another embodiment of the present invention.
FIG. 17 is a cross-sectional view illustrating the shape of another
battery included in the battery modules of the embodiments of the
present invention.
FIG. 18A is a cross-sectional view of the battery module of the
embodiments of the present invention, wherein multiple ones of the
battery of FIG. 17 are used. FIG. 18B is an enlarged
cross-sectional view of the part 18B of FIG. 18A.
DESCRIPTION OF EMBODIMENTS
A battery module according to the present invention is a battery
module including a plurality of batteries aligned and accommodated
in a housing, wherein each of the batteries has an opening portion
at an electrode portion of the battery to release gas generated in
the battery outside the battery, the housing is partitioned by a
circuit board disposed in contact with battery cases around the
electrode portions of the batteries into a storage portion in which
the plurality of batteries are stored, and an exhaust chamber via
which the gas released from the opening portion of the electrode
portion is exhausted outside the housing, the electrode portions of
the batteries are connected to a connector formed on the circuit
board, and the opening portions of the electrode portions are in
communication with the exhaust chamber via through holes formed in
the circuit board.
With this configuration, the circuit board is in contact with the
battery cases around the electrode portions of the batteries, and
the opening portions of the electrode portions are in communication
with the exhaust chamber via the through holes formed in the
circuit board. Therefore, space into which gas emitted as a result
of opening a vent mechanism of the battery is released can be
limited to be within the through hole. Thus, the gas released from
the opening portion of the electrode portion is released into the
exhaust chamber via the through hole, and is further released
outside the housing. Therefore, the gas can be prevented from
entering neighboring batteries. Moreover, space required for
routing power supply interconnects, control interconnects, etc. can
significantly be reduced by the circuit board. As a result, it is
possible to obtain a thin and small battery module which has
substantially the same height as that of the batteries, and which
is highly safe and has high reliability.
Here, it is preferable that the electrode portions of the batteries
be inserted in the through holes of the circuit board. With this
configuration, gas released from the opening portion of the
electrode portion can efficiently be released outside the housing
via the through hole.
Moreover, it is preferable that the circuit board have a layered
structure including a heat-resistant member and an elastic member,
and a lower surface of the elastic member be in contact with the
battery cases. With this configuration, the circuit board can
closely be in contact with the battery cases, so that it is
possible to further improve sealing of the storage portion.
Moreover, it is preferable that the connector be formed on an upper
surface of the circuit board, and a lower surface of the circuit
board be in contact with the battery cases. With this
configuration, the electrode portions inserted in the through holes
of the circuit board can easily be connected to the connector.
Moreover, it is preferable that the height of each electrode
portion be substantially the same as the thickness of the circuit
board. With this configuration, the electrode portions inserted in
the through holes in the circuit board can more easily be connected
to the connector.
Moreover, the size of each through hole formed in the circuit board
is preferably smaller on a side on which the circuit board is in
contact with the battery case than on a side on which the circuit
board is provided with the connector. With this configuration, gas
released from the opening portion of the electrode portion can
efficiently be released outside the housing.
Moreover, the opening portion of each electrode portion may be
provided at an upper surface of the electrode portion, and the
connector connected to the electrode portions may have through
holes formed at least in positions of the connector corresponding
to the opening portions. With this configuration, gas released from
the opening portion of the electrode portion is directly released
into the exhaust chamber via the through hole, so that it is
possible to efficiently release the gas outside the housing.
Moreover, the connector connected to the electrode portions is
preferably formed to straddle the plurality of through holes formed
in the circuit board. With this configuration, the electrode
portions in the through holes can easily be connected to the
connector.
Moreover, it is preferable that the opening portion of each
electrode portion be provided at a side surface of the electrode
portion, and a gap be provided between the circuit board and the
electrode portion in each through hole formed in the circuit board.
With this configuration, gas released from the opening portion of
the electrode portion is released into the exhaust chamber through
the gap, so that the gas can efficiently be released outside the
housing.
Moreover, the plurality of batteries are preferably connected in
parallel by the connector connected to the electrode portions of
the batteries. With this configuration, it is possible to form a
battery module having a high capacity with the size of the battery
module being reduced.
Moreover, the storage portion is sealed by the circuit board. With
this configuration, it can be ensured that gas released from the
opening portion of the electrode portion is released outside the
housing via the through hole and the exhaust chamber without
influencing the other batteries. Note that "sealed" does not
necessarily mean a completely sealed state, but includes such a
sealed state that gas in an amount having no influence returns from
the exhaust chamber to the storage portion.
Moreover, the housing is preferably made of a metal material having
an insulated surface. With this configuration, for example,
ignition due to supply of oxygen through a hole, or the like formed
by melting the housing by emitted high-temperature gas can be
prevented, and exhaustion of the gas via the exhaust chamber can be
ensured.
Moreover, it is preferable that the housing include the storage
portion and a lid body, partition portions be provided in the
storage portion in such a manner that the batteries are
individually stored, and the lid body include rib portions at
positions facing the partition portions of the housing. With this
configuration, heat transmission to neighboring batteries or heat
dissipation can significantly be reduced, and it is ensured that
the circuit board is sandwiched between the partition portions and
the rib portions, so that it is possible to further improve sealing
properties between the storage portion and the exhaust chamber.
Alternatively, the housing may include the storage portion and a
lid body, and a supporting member for holding the circuit board may
further be provided between the lid body and the circuit board.
With this configuration, it is possible to further improve sealing
properties between the storage portion and the exhaust chamber.
A battery pack of the present invention includes multiple ones of
the above battery module which are connected in series and/or
parallel. With this configuration, it is possible to obtain a
battery pack having a given voltage and capacity depending on the
application.
Embodiments of the present invention will be described below with
reference to the drawings, where the use of the same reference
symbols in different drawings indicates similar or identical items.
The present invention is not limited to the below described
contents as long as it is based on the basic features described in
this specification. As a battery, a nonaqueous electrolyte
secondary battery, e.g., a lithium ion secondary battery, in a
cylindrical shape (hereinafter referred to as a "battery") will be
described below by way of example, but of course, the invention is
not limited to these embodiments.
First Embodiment
FIG. 1 is a cross-sectional view of a battery included in a battery
module of a first embodiment of the present invention. Note that
although a battery module including a plurality of batteries
connected in parallel will be described below by way of example, a
battery module including batteries connected in series may be
possible.
As illustrated in FIG. 1, the battery in a cylindrical shape
includes an electrode group 4 in which a positive electrode 1 and a
negative electrode 2 are wound with a separator 3 interposed
therebetween. The positive electrode 1 includes a positive
electrode lead 8 made of, for example, aluminum. The negative
electrode 2 faces the positive electrode 1. One end of the negative
electrode 2 is provided with a negative electrode lead 9 made of,
for example, copper. Insulating plates 10a, 10b are installed above
and below the electrode group 4, and the electrode group 4 with the
insulating plates 10a, 10b is inserted in a battery case 5. The
other end of the positive electrode lead 8 is welded to a sealing
plate 6. The other end of the negative electrode lead 9 is welded
to a bottom of the battery case 5. A nonaqueous electrolyte (not
shown) capable of conducting lithium ions is injected in the
battery case 5. An opening end of the battery case 5 is crimped to
a positive electrode cap 16 included in one electrode portion, a
current cutoff member 18 such as a PTC element, and the sealing
plate 6 via a gasket 7. The positive electrode 1 includes a
positive electrode current collector 1a and a positive electrode
layer 1b containing a positive electrode active material.
Here, the positive electrode cap 16 protrudes from an upper surface
5A of the opening end of the battery case 5. A side surface of the
positive electrode cap 16 is provided with an opening portion 17 to
release gas resulting from opening of a vent mechanism 19 such as a
safety valve due to a problem in the electrode group 4. Note that
the height of a portion of the positive electrode cap 16 which
protrudes from the upper surface 5A is almost the same as the
thickness of, for example, a circuit board, which will be described
below. Although an example in which the positive electrode cap 16
is provided to protrude from the upper surface 5A of the battery
case 5 will be described below, a battery having a positive
electrode cap provided to be flush with an upper surface 5A of a
battery case 5 may be possible.
Here, the positive electrode layer 1b contains, as the positive
electrode active material, for example, a lithium-containing
compound oxide such as LiCoO.sub.2, LiNiO.sub.2, Li2MnO.sub.4, a
mixture of these materials, or a complex compound of these
materials. The positive electrode layer 1b further contains a
conductive agent and a binder. Examples of the conductive agent
include graphites such as natural graphite and artificial graphite,
and carbon blacks such as acetylene black, ketjen black, channel
black, furnace black, lamp black, and thermal black. Examples of
the binder include PVDF, polytetrafluoroethylene, polyethylene,
polypropylene, an aramid resin, polyamide, polyimide, etc.
Moreover, as the positive electrode current collector 1a used for
the positive electrode 1, aluminum (Al), carbon (C), or a
conductive resin can be used.
As the nonaqueous electrolyte, an electrolyte solution obtained by
dissolving a solute in an organic solvent, or a so-called polymer
electrolyte layer including the electrolyte solution solidified by
macromolecules can be used. As the solute of the nonaqueous
electrolyte, LiPF.sub.6, LiBF.sub.4, LiClO.sub.4, LiAlCl.sub.4,
LiSbF.sub.6, LiSCN, LiCF.sub.3SO.sub.3, LiN(CF.sub.3CO.sub.2),
LiN(CF.sub.3SO.sub.2).sub.2, or the like can be used. Furthermore,
as the organic solvent, for example, ethylene carbonate (EC),
propylene carbonate, butylene carbonate, vinylene carbonate,
dimethyl carbonate (DMC), diethyl carbonate, ethyl methyl carbonate
(EMC), or the like can be used.
Moreover, a negative electrode current collector 11 of the negative
electrode 2 can be metal foil made of stainless steel, nickel,
copper, titanium, or the like, or thin film made of carbon or a
conductive resin.
Furthermore, as negative electrode layers 15 of the negative
electrode 2, a negative electrode active material, e.g., silicon
(Si), tin (Sn), or a carbon material such as graphite, which is
capable of reversibly inserting and extracting lithium ions, and
has a theoretical capacity density of 833 mAh/cm.sup.3 or higher
can be used.
A battery module of the first embodiment of the present invention
will be described in detail below with reference to FIGS. 2A-2C, 3,
4A, 4B, and 5.
FIG. 2A is a perspective view illustrating the battery module of
the first embodiment of the present invention. FIG. 2B is a
cross-sectional view along the line 2B-2B of FIG. 2A. FIG. 2C is an
enlarged cross-sectional view of the part 2C of FIG. 2B. FIG. 3 is
an exploded perspective view of the battery module of the first
embodiment of the present invention.
As illustrated in FIGS. 2A and 3, a battery module 100 includes a
housing 50 made of an insulating resin material such as a
polycarbonate resin, and a lid body 20 fitting into the housing
50.
As illustrated in FIGS. 2B and 3, a battery unit 40 is stored in
the housing 50. The battery unit 40 is formed in such a manner that
a plurality of batteries whose positive electrode caps 16 are
aligned in the same direction are electrically connected in
parallel by connectors 32, 34 of a circuit board 30. Moreover, a
connection plate 33 by which bottoms each serving as one of
electrode portions (negative electrode) of the battery are
connected in parallel is connected to the connector 34 of the
circuit board 30 by extension portions 33A each extending from a
part of the connection plate 33.
Moreover, as illustrated in FIG. 2C, the positive electrode caps 16
protruding from the battery cases 5 are inserted inside through
holes 36 in the circuit board 30, where the through holes 36 are
provided for the batteries, respectively. The positive electrode
caps 16 are connected to the connector 32 of the circuit board 30.
Here, the circuit board 30 is in contact with and closely attached
to the battery cases 5, and each through hole 36 has a gap 36A so
that the opening portion 17 provided in the side surface of the
positive electrode cap 16 is not covered. The gap 36A serves as
space into which gas emitted from the opening portion 17 of the
positive electrode cap 16 on the occurrence of a problem in the
battery is released.
Then, as illustrated in FIGS. 2B and 3, the emitted gas passes
through the gap 36A between the connector 32 of the circuit board
30 and the positive electrode cap in the through hole 36, and also
through space in an exhaust chamber 24 of the lid body 20, and then
is released from an opening 26 in communication with the
outside.
Components included in the battery module 100 will be described
below with reference to the drawings.
First, as illustrated in FIG. 3, the housing 50 includes an opening
end on a side on which the lid body 20 is fitted into the housing
50, and a storage portion 54 into which the plurality of batteries
are installed from the opening end side. Here, when batteries each
have, for example, an outer diameter of 18 mm, and a height of 65
mm, the height of the storage portion 54 is approximately a value
obtained by adding the thickness of the connection plate 33 to 65
mm.
Moreover, as illustrated in FIGS. 2B and 3, the lid body 20
includes the exhaust chamber 24 formed by external walls 22, and
the opening 26 provided in a part of the external walls 22.
Moreover, as illustrated in FIG. 2C, the circuit board 30 has a
layered structure including at least two layers, a heat-resistant
member 30a made of, for example, a glass and epoxy substrate or
polyimide, and an elastic member 30b having, for example, rubber
elasticity. Since the elastic member 30b elastically deforms and
comes closely in contact with the upper surfaces 5A of the battery
cases 5, a high degree of air-tightness can be ensured. Note that
as long as a high degree of air-tightness can be ensured, it is not
particularly necessary for the circuit board 30 to have the layered
structure. Moreover, the circuit board 30 includes the connector 32
which is to be connected to the positive electrode caps 16 of the
batteries inserted in the through holes 36, and the connector 34
which is to be connected to the extension portions 33A of the
connection plate 33 connecting the other electrodes (e.g., negative
electrodes) of the batteries in parallel. The connector 32 is
provided to straddle the through holes 36 such that the connector
32 does not completely cover the through holes 36. Note that the
connector 32 and the connection plate 33 are made of, for example,
a nickel plate, a Cu plate, an Al plate, or a lead wire, and the
connection plate 33 is connected to the connector 34 made of copper
foil, or the like by, for example, soldering. Moreover, connection
of the positive electrode caps 16 to the connector 32, and
connection of the negative electrodes to the connection plate 33
are achieved by, for example, electric welding or spot welding.
In this way, the batteries included in the battery module can be
connected by the circuit board, so that it is possible to
significantly reduce space required for routing a power supply
interconnect or a control interconnect. Moreover, the opening
portions of the positive electrode caps of the batteries are placed
in the through holes of the circuit board. As a result, gas emitted
from a battery on the occurrence of a problem cannot enter
neighboring battery cases, and thus even if the gas is ignited for
combustion, flames can be prevented from entering the neighboring
battery cases, and blocking the effect of the flames can be
ensured.
The operation and advantages of the battery module 100 of the
present embodiment in case of, for example, excessive heat
generation in one of the batteries connected in parallel in the
battery module 100 will be described below with reference to FIGS.
4A and 4B.
FIG. 4A is a cross-sectional view illustrating exhaustion of gas
emitted in case of, for example, excessive heat generation in one
of the batteries in the battery module 100 of the present
embodiment. FIG. 4B is an enlarged cross-sectional view
illustrating the part 4B of FIG. 4A.
First, as illustrated in FIG. 4B, excessive heat is generated in
one of the batteries of the battery module 100, which increases the
gas pressure of gas generated in the battery case, thereby
operating, for example, a safety valve serving as a vent mechanism,
so that gas 45 is emitted from the battery case. Then, the emitted
gas 45 is emitted through the opening portion 17 of the positive
electrode cap 16 into the gap 36A of the through hole 36 inside
which the positive electrode cap 16 is inserted.
Next, as illustrated in FIG. 4A, the gas 45 does not fill the gap
36A, but is exhausted into the exhaust chamber 24 of the lid body
20 via the through hole 36 which is not covered by the connector 32
of the circuit board 30. Then, the gas 45 is eventually released
outside the battery module 100 through the opening 26 provided in
the lid body 20.
Here, when the gas 45 is rapidly emitted from the battery having a
problem in the battery module 100, a risk that combustion of the
gas is produced by, for example, ignition generally increases.
However, in the battery module 100 having the above configuration
of the present invention, the amount of oxygen in the gap 36A in
the through hole 36 is limited, and no oxygen is further supplied
from the outside. Thus, the possibility of ignition of the gas is
very low. As a result, the gas 45 is exhausted in a gaseous state
via the through hole 36 of the circuit board 30. Therefore,
explosive expansion due to the ignition of the gas is not caused.
Thus, there is no rupture of the battery module.
According to the present embodiment, the battery module is stored
in the storage portion of the housing, under a sealed state by at
least the circuit board and the housing, and gas emitted from a
battery having a problem can be released, in a gaseous state,
outside the battery module through the gap of the through hole of
the circuit board. As a result, it is possible to obtain a battery
module in which the gas is not ignited for combustion or to
generate smoke, and which is highly safe.
Moreover, the batteries included in the battery module can be
stored in the storage portion of the housing, under the sealed
state by at least the circuit board and the housing, so that it is
not necessary to individually store the batteries. As a result, the
battery module can easily be downsized. Moreover, space required
for routing the power supply interconnect or the control
interconnect can significantly be reduced by the circuit board. As
a result, it is possible to obtain a battery module which is
smaller in size, and has high safety and high reliability.
Note that in the present embodiment, the lid body 20 made of an
insulating material such as a polycarbonate resin has been
described, but the invention is not limited to this embodiment. For
example, a metal material such as aluminum, or the metal material
covered with an insulating resin may be used. With this
configuration, the mechanical strength can be improved to obtain a
lid body having a reduced thickness, thereby further downsizing the
battery module. Moreover, high thermal-conductivity of the metal
material enhances the capability of cooling emitted gas, so that it
is also possible to obtain a highly reliable battery module which
is less likely to be ignited. Moreover, forming a hole by melting
the lid body by the emitted high-temperature gas is prevented to
prevent, for example, ignition by supply of oxygen through the
hole, which makes it possible to ensure exhaustion of the gas via
the exhaust chamber.
Moreover, in the present embodiment, a structure in which the lid
body 20 is fitted into the housing 50 to support the circuit board
30 by the external walls 22 of the lid body 20, the housing 50, and
the upper surfaces 5A of the battery cases 5 has been described,
but the present invention is not limited to this embodiment. For
example, as illustrated in FIG. 5 which is an exploded perspective
view of a battery module, a supporting member 65 configured to
support the circuit board 30 may be interposed between the lid body
20 and the circuit board 30. In this case, the supporting member 65
includes an external frame 66 for supporting at least an external
circumferential portion of the circuit board 30, and supporting
portions 68. The supporting portions 68 are provided in positions
facing the housing 50, and facing positions at which the upper
surfaces 5A of the battery cases 5 are in contact with each other.
Here, when the space of the exhaust chamber of the lid body 20 is
reduced due to the supporting portions 68 of the supporting member
65, a recessed portion, a hole, or the like which is in
communication with the opening of the lid body 20 may be provided
in part of the supporting portion 68. In this way, it is possible
to ensure fixing of the circuit board 30 by the housing 50, the
upper surfaces 5A of the battery cases 5, and the supporting
portions 68 of the supporting member 65. As a result, deformation
of the circuit board due to pressure caused by emitted gas is
reduced, and heat or gas entering battery cases of neighboring
batteries is more efficiently reduced, so that it is possible to
obtain a battery module having further improved reliability and
safety.
Alternatively, in the exhaust chamber 24 of the lid body 20, rib
portions 28 each having an opening hole 28A may be provided in
positions facing the housing 50 and the upper surfaces 5A of the
battery cases 5 as illustrated in FIG. 6, instead of providing the
supporting member 65. In this way, the circuit board 30 can be
fixed by the housing, the upper surfaces 5A of the battery cases 5,
and the rib portions 28 of the lid body 20, and the size or the
thickness of the battery module can further be reduced.
Moreover, in the present embodiment, the circuit board provided
with the power supply interconnect such as the connector has been
described by way of example, but the present invention is not
limited to this embodiment. For example, the circuit board may be
provided with voltage detecting interconnects for detecting
voltages of batteries, or temperature sensing interconnects for
sensing temperatures of the batteries. Here, temperature sensing
devices such as thermistors are connected to the temperature
sensing interconnects, and the temperature sensing devices are
brought into contact with the batteries, so that the sensing
devices can sense the temperatures of the batteries. In this way,
the voltages and the temperatures of the plurality of batteries can
individually be detected and controlled. As a result, control is
possible in consideration of, for example, variations of the
characteristics or aging variation of the batteries, so that it is
possible to further increase reliability and safety. Note that the
pattern width of the voltage detecting interconnects or the
temperature sensing interconnects on the circuit board can
significantly be smaller than that of the power supply
interconnect. This is because a high current flows through the
power supply interconnect, and thus power loss due to interconnect
resistance has to be reduced, whereas the voltage detecting
interconnects or the temperature sensing interconnects can perform
detection/sensing by a very low current. Thus, the power supply
interconnect and pairs of the voltage detecting interconnects and
the temperature sensing interconnects can efficiently be arranged
on the circuit board, so that space required for interconnection
can significantly be reduced.
Moreover, in the present embodiment, the housing having an opening
end on its one side has been described by way of example, but the
present invention is not limited to this embodiment. For example,
as illustrated in FIG. 7, a housing 50 may include a frame body 50A
and a closing member 50B. The frame body 50A has opening ends on
both ends thereof to store a plurality of batteries. The closing
member 50B closes one of the opening ends. With this configuration,
assembly properties and workability such as connection of the
batteries to the circuit board or to the connection plate are
improved, thereby obtaining a battery module having high
productivity. Alternatively, a frame body 50C having a partition
portion 52 for individually storing batteries as illustrated in
FIG. 8 can be used instead of the frame body 50A of FIG. 7. With
this configuration, transmission or dissipation of excessive heat
generated in a battery having a problem to neighboring batteries
can further be reduced by the partition portion 52. Thus, it is
possible to obtain a battery module having higher reliability and
higher safety.
Moreover, in the present embodiment, the case where the shape of
the through hole formed in the circuit board is the same in the
thickness direction has been described by way of example, but the
present invention is not limited to this embodiment. For example,
as illustrated in FIG. 9, the size of the through hole can be
smaller at a position of the circuit board closely in contact with
the upper surface of the battery case than at a position of the
circuit board close to the connector 32. With this configuration,
the release efficiency of gas emitted from the opening portion of
the positive electrode cap of the battery into the exhaust chamber
of the lid body can be increased (the release resistance can be
reduced). Furthermore, the area where the circuit board is closely
in contact with the upper surface of the battery case is increased
to significantly reduce gas entering the battery case side, so that
reliability and safety can be improved.
Second Embodiment
FIG. 10 is a cross-sectional view of a battery included in a
battery module of a second embodiment of the present invention.
As illustrated in FIG. 10, the battery of the present embodiment is
different from the battery of the first embodiment in that an upper
surface of a positive electrode cap 16 serving as an electrode
portion of the battery is provided with an opening portion 77. Note
that components other than batteries are the same as those of the
first embodiment, and thus the description thereof may be
omitted.
The battery module including the batteries of the present
embodiment will be described in detail below with reference to
FIGS. 11A-11C, and 12.
FIG. 11A is a perspective view illustrating the battery module of
the second embodiment of the present invention. FIG. 11B is a
cross-sectional view along the line 11B-11B of FIG. 11A. FIG. 11C
is an enlarged cross-sectional view of the part 11C of FIG. 11 B.
FIG. 12 is an exploded perspective view of the battery module of
the second embodiment of the present invention.
As illustrated in FIGS. 11A and 12, a battery module 200 includes a
housing 50, and a lid body 20 fitting into the housing 50. The
housing 50 is made of an insulating resin material or a metal
material whose surface is covered by a resin for insulation.
As illustrated in FIGS. 11B and 12, a plurality of batteries are
stored in a storage portion 54 of the housing 50. Positive
electrode caps of the batteries are aligned in the same direction,
and electrically connected in parallel by a connector 32 of a
circuit board 30. Moreover, a connection plate 33 by which bottoms
each serving as one of electrode portions (negative electrode) of
the battery are connected in parallel is connected to a connector
34 of the circuit board 30 by extension portions 33A each extending
from a part of the connection plate 33.
Moreover, as illustrated in FIG. 11C, the positive electrode caps
16 protruding from battery cases 5 are inserted inside through
holes 36 in the circuit board 30, where the through holes 36 are
provided for the batteries, respectively. The positive electrode
caps 16 are connected to the connector 32. The circuit board 30 is
in contact with and closely attached to the battery cases 5, and
each through hole 36 has a gap 36A between its inner side surface
and the positive electrode cap 16. Here, the connector 32 has a
through hole 32a in a position corresponding to the opening portion
77 so that the opening portion 77 formed in the upper surface of
the positive electrode cap 16 is not covered. Gas emitted through
the opening portion 77 of the positive electrode cap 16 on the
occurrence of a problem in the battery is released via the through
hole 32a.
Then, as illustrated in FIGS. 11B and 12, the emitted gas passes
through the through hole 32a of the connector 32 of the circuit
board 30 and through an exhaust chamber (not shown) of the lid body
20, and then is released from an opening 26 in communication with
the outside.
Components included in the battery module 200 will be described
below with reference to the drawings. Note that the configurations
of the housing 50 and the lid body 20 of the battery module 200 are
the same as those of the first embodiment, and thus the description
thereof is omitted, and the circuit board which is different from
that of the first embodiment will mainly be described.
As illustrated in FIGS. 11C and 12, the circuit board 30 has a
layered structure including at least two layers, a heat-resistant
member 30a made of, for example, a glass and epoxy substrate or
polyimide, and an elastic member 30b having, for example, rubber
elasticity. The elastic member 30b elastically deforms and comes
closely in contact with the upper surfaces 5A of the battery cases
5, thereby ensuring a high degree of air-tightness.
Moreover, the circuit board 30 includes the connector 32 and the
connector 34. The connector 32 is to be connected to the positive
electrode caps 16 of the batteries of the battery module, the
positive electrode caps 16 being inserted in the through holes 36.
The connector 34 is to be connected to the extension portions 33A
of the connection plate 33 connecting the other electrodes of the
batteries (e.g., negative electrodes) in parallel. The connector 32
is provided with through holes 32a so that the connector 32 does
not cover the opening portions 77 of the positive electrode caps
16.
In this way, batteries of battery modules can be connected by the
circuit board, so that it is possible to significantly reduce space
required for routing a power supply interconnect or a control
interconnect. Moreover, the opening portion of the positive
electrode cap of each battery is directly in communication with an
exhaust chamber 24 of the lid body 20 via the through hole 32a of
the connector 32. Therefore, gas emitted from a battery in a
failure state is not directly emitted to the circuit board 30, and
thus deformation of the circuit board 30 can significantly be
reduced. As a result, even if the gas is ignited for combustion, it
is possible to significantly reduce the gas and flames entering
neighboring battery cases.
The operation and advantages of the battery module 200 of the
present embodiment in case of, for example, excessive heat
generation in one of the batteries connected in parallel in the
battery module 200 will be described below with reference to FIGS.
13A and 13B.
FIG. 13A is a cross-sectional view illustrating exhaustion of gas
emitted in case of, for example, excessive heat generation in one
of the batteries in the battery module 200 of the present
embodiment. FIG. 13B is an enlarged cross-sectional view
illustrating the part 13B of FIG. 13A.
First, as illustrated in FIG. 13B, excessive heat is generated in
one of the batteries of the battery module 200, which increases the
gas pressure of gas generated in the battery case, thereby
operating, for example, a safety valve serving as a vent mechanism,
so that gas 45 is emitted from the battery case 5.
Next, as illustrated in FIG. 13A, the emitted gas 45 is emitted
from the opening portion 77 of the positive electrode cap 16 via
the through hole 32a of the connector 32 into the exhaust chamber
24 of the lid body 20. Then, the gas is eventually released outside
the battery module 200 through the opening 26 provided in the lid
body 20.
In the battery module 200 of the present invention, the gas 45 is
exhausted in a gaseous state via the through hole 32a of the
connector 32 of the circuit board 30. Therefore, explosive
expansion due to ignition of the gas is not caused. Thus, there is
no rupture of the battery module.
According to the present embodiment, the plurality of batteries are
stored in the storage portion of the housing, under a sealed state
by at least the circuit board and the housing, and gas emitted from
a battery having a problem can be released, in a gaseous state,
from the through hole of the connector of the circuit board through
the exhaust chamber of the lid body outside the battery module. As
a result, it is possible to obtain a battery module in which the
gas is not ignited for combustion or to generate smoke, and which
is highly safe.
Moreover, the plurality of batteries can be stored in the storage
portion of the housing, under the sealed state by at least the
circuit board and the housing, so that it is not necessary to
individually store the batteries. As a result, the battery module
can easily be downsized. Moreover, space required for routing the
power supply interconnect or the control interconnect can
significantly be reduced by the circuit board. As a result, it is
possible to obtain a battery module which is smaller in size, and
has high safety and high reliability.
Note that in the present embodiment, a configuration having the gap
36A between the positive electrode cap 16 of the battery and the
circuit board in the through hole 36 of the circuit board in which
the positive electrode cap 16 is inserted has been described by way
of example, but the present invention is not limited to this
embodiment. For example, as illustrated in FIGS. 14A-14C, through
holes may have a shape substantially the same as that of the
positive electrode caps 16. In this way, positioning of the opening
portion 77 of each battery to the corresponding through hole 32a of
the connector is easy, and variations in opening area of the
through holes 32a due to displacement can be reduced. As a result,
it is possible to obtain a battery module having higher reliability
and safety.
Moreover, it is, of course, possible to apply the configuration
described in the first embodiment with reference to FIGS. 5-8 to
the battery module of the second embodiment, and similar advantages
can be obtained.
Third Embodiment
A battery pack of a third embodiment of the present invention will
be described in detail below with reference to FIGS. 15A and
15B.
FIGS. 15A and 15B are assembled perspective views of the battery
pack of the third embodiment of the present invention.
In FIG. 15A, four battery modules of the above embodiments are
arranged in parallel, and are connected by a connection member 450,
thereby forming a battery pack 400. Alternatively, in FIG. 15B,
battery modules of the above embodiments are parallelly arranged in
pairs, the obtained two pairs of the battery modules are stacked in
two tiers in the vertical direction, and are connected by a
connection member 550, thereby forming a battery pack 500. Here,
the battery modules are connected by the connection member, in
parallel, in series, or in parallel and in series, thereby forming
the battery pack.
According to the present embodiment, highly versatile battery packs
having a required voltage and electric capacity can easily be
obtained by arbitrarily combining battery modules in consideration
of installation space depending on the application.
Moreover, according to the present embodiment, as in the above
embodiments, even when a problem occurs in any one of the battery
modules, emitted gas is not ignited, and can be exhausted, in a
gaseous state, to the outside. As a result, explosive expansion due
to ignition of gas is not caused. Thus, it is possible to obtain a
battery pack in which no battery module ruptures, and which is safe
and has high reliability.
Other Embodiments
Other embodiments of the battery module of the present invention
will be described below with reference to FIG. 16.
FIG. 16 is an exploded perspective view illustrating a battery
module 600 of another embodiment of the present invention. Here,
the battery module 600 is different from those of the above
embodiments in that a plurality of battery units 640 each including
batteries connected in parallel are two-dimensionally arranged, is
connected in series, and is integrally stored. Note that in FIG.
16, the battery module 600 will be described by way of example,
where the battery module 600 includes seven battery units 640
connected in series, and each battery unit 640 includes eleven
batteries connected in parallel. For example, when lithium ion
batteries each having a capacity of 2500 mAh and an average voltage
3.6 V are used, a battery unit set 645 having a voltage of 25.2 V
(3.6 V.times.7) and a capacity of 27.5 Ah (2.5 Ah.times.11) is
obtained.
That is, as illustrated in FIG. 16, the battery module 600 includes
a housing 660 having a storage portion 664, the battery unit set
645 which is stored in the storage portion 664, and in which seven
battery units each including eleven batteries connected in parallel
are connected in series, a circuit board 630 and connection plates
650 by which the batteries included in the battery unit set 645 are
connected in series and in parallel, and a lid body 620 fitting
into the housing 660 in which these members are stored under a
sealed state.
The circuit board 630 includes through holes 636 in positions
corresponding to positive electrode caps of the batteries of the
battery unit set 645. The circuit board 630 is provided with
connectors 632 such that the connectors 632 do not completely cover
the through holes 636. The connectors 632 connect the batteries
included in the battery units 640 in parallel. The circuit board
630 is, as in the above embodiments, arranged closely in contact
with upper surfaces of battery cases.
Moreover, each connection plate 650 parallelly connects negative
electrodes each serving as one of electrode portions of the battery
of the battery unit 640, and is connected to connection portions
635 of the circuit board 630 via extension portions 650A provided
at portions of the connection plate 650. The connection rand
portions 635 are connected to the connector 632 of a neighboring
battery unit 640, thereby connecting the battery units 640 in
series.
Moreover, the lid body 620 includes an opening (not shown) to
release emitted gas via an exhaust chamber (not shown) to the
outside. Here, the opening may include openings provided for the
battery units 640, respectively, or one opening may be provided for
all the battery units 640.
According to the above embodiments, it is possible to obtain
advantages similar to those of the first and second embodiments,
and to obtain a battery module which is further downsized by
integrally forming the housing.
Note that in the embodiments, a battery shape in which the positive
electrode cap 16 serving as an electrode portion protrudes from the
upper surface 5A of the battery case 5 has been described by way of
example, but the present invention is not limited to this
embodiment. For example, as described below with reference to FIGS.
17, 18A, and 18B, a battery module may include batteries each
having a positive electrode cap 16 provided to substantially be
flush with an upper surface 5A of a battery case 5.
FIG. 17 is a cross-sectional view illustrating the shape of another
battery included in the battery modules of the embodiments of the
present invention. FIG. 18A is a cross-sectional view of the
battery module of the embodiments of the present invention, wherein
multiple ones of the battery of FIG. 17 are used. FIG. 18B is an
enlarged cross-sectional view of the part 18B of FIG. 18A.
That is, as illustrated in FIGS. 18A and 18B, the present
embodiment is different from the above embodiments in that the
positive electrode cap 16 provided to substantially be flush with
the upper surface 5A of the battery case 5 is connected to a
connector 32 of a circuit board 30, wherein the circuit board 30 is
provided with through holes 36 at positions corresponding to the
positive electrode caps 16, and the connector 32 is in a form of a
downwardly convex portion 32C. The other configurations are the
same as those of the above embodiments, and thus the description
thereof is omitted.
With this configuration, advantages similar to those of the above
embodiments can be obtained. Moreover, regardless of the positional
relationship of the positive electrode caps of the electrode
portions of the batteries, a thin and small battery module 300 can
be obtained. Note that the examples described in the embodiments
are, of course, applicable to this embodiment.
Moreover, in the embodiments, charge/discharge of the battery
module, and control circuits for detecting and controlling
temperature or voltages are not described in particular or
illustrated in the figures, but the control circuits may, of
course, be provided outside or inside the battery module.
Moreover, in the embodiments, cylindrical batteries are described
as the battery modules by way of example, but the invention is not
limited to these embodiments. For example, square batteries can be
used.
Moreover, in the embodiments, their configurations are compatible
with each other.
INDUSTRIAL APPLICABILITY
The present invention is applicable to battery modules and battery
packs for vehicles, bicycles, or electric tools, in particular,
hybrid vehicles or electric vehicles which require large
capacities, high voltages, and also high reliability and
safety.
DESCRIPTION OF REFERENCE CHARACTERS
1 Positive Electrode 1a Positive Electrode Current Collector 1b
Positive Electrode Layer 2 Negative Electrode 3 Separator 4
Electrode Group 5 Battery Case 5A Upper Surface 6 Sealing Plate 7
Gasket 8 Positive Electrode Lead 9 Negative Electrode Lead 10a, 10b
Insulating Plate 11 Negative Electrode Current Collector 15
Negative Electrode Layer 16 Positive Electrode Cap (Electrode
Portion) 17, 77 Opening Portion 18 Current Cutoff Member 19 Vent
Mechanism 20, 620 Lid Body 22 Outer Circumferential Wall 24 Exhaust
Chamber 26 Opening 28 Rib Portion 28A Opening Hole 30, 630 Circuit
Board 30a Heat-Resistant Member 30b Elastic Member 32, 34, 632
Connector 32a Through Hole 32C Convex Portion 33, 650 Connection
Plate 33A, 650A Extension Portion 36, 636 Through Hole 36A Gap 40,
640 Battery Unit 45 Gas 50, 660 Housing 50A, 50C Frame Body 50B
Closing Member 52 Partition Portion 54, 664 Storage Portion 65
Supporting Member 66 External Frame 68 Supporting Portion 100, 200,
300, 600 Battery Module 400, 500 Battery Pack 450, 550 Connection
Member 635 Connection Portion 645 Battery Unit Set
* * * * *